Abstract

REBa2Cu3Oy (RE123 or REBCO, RE = rare earth elements) bulk high-temperature superconductors have a potential perspective for large-scale engineering applications. However, the cost of REBCO bulk production is rather high, considering high failure rates, expensive RE materials, and Pt or Ag addition. Using the cold-seeding in the top-seeded melt growth, a simple and feasible process, we succeeded in recycling the failed REBCO (RE = Y) bulks. The distinctive feature of this recycling process is the use of YBCO-buffered NdBCO films as seeds, which have high thermal stability and can endure a maximum processing temperature (Tmax) up to 1120 °C to enable full decomposition of solid REBCO. Three typical microstructures were recognized in the failed samples attributed to the inherent differences in the non-optimized growth heating profiles. Preferential recycling procedures were chosen according to the difficulty of the failed-samples decomposition, which has a certain connection with the microstructures of the failed bulks. Finally, after oxygenation, the recycled bulks demonstrate good superconducting properties.

Received 21 March 2012Accepted 26 April 2012Published online 23 May 2012

Acknowledgments:

The authors are grateful for financial support from the NSFC (Grant Nos. 51011140073, 51172143, and 51072115), the MOST of China (Grant No. 2012CB821400), and the SSTCC (Grant No. 10JC1406800). The authors thank Northwest Institute For Non-ferrous Metal Research (Xi’an 710016, China) for providing commercial powders. They also thank Instrumental Anal Ctr. of Shanghai Jiao Tong Univ. (Shanghai 200240, China) for offering a PPMS characterization. They also thank T. Mertelj for comments critically reading the manuscript within the bilateral project BI-CN/11-13-014.